ODK Collect is an Android app for filling out forms. It is designed to be used in resource-constrained environments with challenges such as unreliable connectivity or power infrastructure. ODK Collect is part the ODK Project, a free and open-source set of tools which help organizations author, field, and manage mobile data collection solutions. Learn more about the ODK project and its history here and read about example ODK deployments here.

ODK Collect renders forms that are compliant with the ODK XForms standard, a subset of the XForms 1.1 standard with some extensions. The form parsing is done by the JavaRosa library which Collect includes as a dependency.

• Learn more about ODK Collect
• Release cycle
• Setting up your development environment
• Testing a form without a server
• Using APIs for local development
• Debugging JavaRosa
• Contributing code
• Contributing translations
• Contributing testing
• Downloading builds
• Creating signed releases for Google Play Store
• Troubleshooting

• ODK website: https://getodk.org
• ODK Collect usage documentation: https://docs.getodk.org/collect-intro/
• ODK forum: https://forum.getodk.org
• ODK developer Slack chat: https://slack.getodk.org

Releases can be requested by any community member and generally happen every 2 months.

Before release we perform a "code freeze" (we stop merging pull requests) and then carry out regression testing. If any problems are found, the release is blocked until we can merge fixes. Once the process is complete, @yanokwa pushes the releases to the Play Store. The code is "unfrozen" after a short grace period to make hot fixing easier.

At the beginning of each release cycle, @grzesiek2010 updates all dependencies that have compatible upgrades available and ensures that the build targets the latest SDK.

We try to make sure that all issues in the issue tracker are as close to fully specified as possible so that they can be closed by a pull request. Feature suggestions should be described in the forum Features category and discussed by the broader user community. Once there is a clear way forward, issues should be filed on the relevant repositories. More controversial features will be discussed as part of the Technical Steering Committee's roadmapping process.

1. Download and install Git and add it to your PATH

2. Download and install Android Studio

3. Fork the collect project (why and how to fork)

4. Clone your fork of the project locally. At the command line:

    git clone https://github.com/YOUR-GITHUB-USERNAME/collect
   

   If you prefer not to use the command line, you can use Android Studio to create a new project from version control using https://github.com/YOUR-GITHUB-USERNAME/collect.

5. Use Android Studio to import the project from its Gradle settings. To run the project, click on the green arrow at the top of the screen.

6. Windows developers: continue configuring Android Studio with the steps in this document: Developing ODK Collect on Windows.

7. Make sure you can run unit tests by running everything under collect_app/src/test/java in Android Studio or on the command line:

   ./gradlew testDebug
   

8. Make sure you can run instrumented tests by running everything under collect_app/src/androidTest/java in Android Studio or on the command line:

   ./gradlew connectedAndroidTest
   

   Note: You can see the emulator setup used on CI in .circleci/config.yml.

When you first run Collect, it is set to download forms from https://opendatakit.appspot.com/, the demo server. You can sometimes verify your changes with those forms but it can also be helpful to put a specific test form on your device. Here are some options for that:

1. The All Widgets form from the default Aggregate server is here. You can also try example forms and test forms or make your own.

2. Convert the XLSForm (xlsx) to XForm (xml). Use the ODK website or XLSForm Offline or pyxform.

3. Once you have the XForm, use adb to push the form to your device (after enabling USB debugging) or emulator.

   adb push my_form.xml /sdcard/odk/forms/
   

4. Launch ODK Collect and tap Fill Blank Form. The new form will be there.

Certain functions in ODK Collect depend on cloud services that require API keys or authorization steps to work. Here are the steps you need to take in order to use these functions in your development builds.

Google Drive and Sheets APIs: When the "Google Drive, Google Sheets" option is selected in the "Server" settings, ODK Collect uses these APIs to store submitted form data in Google Sheets and submitted media in Google Drive. To enable these APIs:

• Follow these instructions to generate a signing certificate fingerprint and register the application with the Google API Console.
• Enable the Google Drive API.
• Enable the Google Sheets API.
• Copy the oauth clientID from the developer console into the client_id of collect_app/google-services.json file

Google Maps API: When the "Google Maps SDK" option is selected in the "User interface" settings, ODK Collect uses the Google Maps API for displaying maps in the geospatial widgets (GeoPoint, GeoTrace, and GeoShape). To enable this API:

• Get a Google Maps API key. Note that this requires a credit card number, though the card will not be charged immediately; some free API usage is permitted. You should carefully read the terms before providing a credit card number.
• Edit or create collect_app/secrets.properties and set the GOOGLE_MAPS_API_KEY property to your API key. You should end up with a line that looks like this:

  GOOGLE_MAPS_API_KEY=AIbzvW8e0ub...
  

Mapbox Maps SDK for Android: When the "Mapbox SDK" option is selected in the "User interface" settings, ODK Collect uses the Mapbox SDK for displaying maps in the geospatial widgets (GeoPoint, GeoTrace, and GeoShape). To enable this API:

• Create a Mapbox account. Note that signing up with the "Pay-As-You-Go" plan does not require a credit card. Mapbox provides free API usage up to the monthly thresholds documented at https://www.mapbox.com/pricing. If your usage exceeds these thresholds, you will receive e-mail with instructions on how to add a credit card for payment; services will remain live until the end of the 30-day billing term, after which the account will be deactivated and will require a credit card to reactivate.
• Find your access token on your account page.
• Edit or create collect_app/secrets.properties and set the MAPBOX_ACCESS_TOKEN property to your access token. You should end up with a line that looks like this:

  MAPBOX_ACCESS_TOKEN=pk.eyJk3bumVp4i...
  

JavaRosa is the form engine that powers Collect. If you want to debug or change that code while running Collect, you have two options. You can include the source tree as a module in Android Studio or include a custom jar file you build.

Source tree

1. Get the code from the JavaRosa repo
2. In Android Studio, select File -> New -> New Module -> Import Gradle Project and choose the project
3. In Collect's build.gradle file, find the JavaRosa section:

   implementation("org.getodk:javarosa:x.y.z") {
       ...
   }

4. Replace the first line like this, using javarosa or whatever name you specified when importing:

   implementation (project(path: ':javarosa')) {
       ...
   }

Jar file

1. In JavaRosa, change the version in build.gradle and build the jar

   jar {
       baseName = 'javarosa'
       version = 'x.y.z-SNAPSHOT'

2. In Collect, add the path to the jar to the dependencies in build.gradle

   compile files('/path/to/javarosa/build/libs/javarosa-x.y.z-SNAPSHOT.jar')

Any and all contributions to the project are welcome. ODK Collect is used across the world primarily by organizations with a social purpose so you can have real impact!

Issues tagged as good first issue should be a good place to start. There are also currently many issues tagged as needs reproduction which need someone to try to reproduce them with the current version of ODK Collect and comment on the issue with their findings.

If you're ready to contribute code, see the contribution guide.

If you know a language other than English, consider contributing translations through Transifex.

Translations are updated right before the first beta for a release and before the release itself. To update translations, download the zip from https://www.transifex.com/getodk/collect/strings/. The contents of each folder then need to be moved to the Android project folders. A quick script like the one in this gist can help. We currently copy everything from Transifex to minimize manual intervention. Sometimes translation files will only get comment changes. When new languages are updated in Transifex, they need to be added to the script above. Additionally, ApplicationConstants.TRANSLATIONS_AVAILABLE needs to be updated. This array provides the choices for the language preference in general settings. Ideally the list could be dynamically generated.

All pull requests are verified on the following devices (ordered by Android version):

• Huawei Y560-L01 - Android 5.1.1
• Sony Xperia Z3 D6603 - Android 6.0.1
• Samsung Galaxy S7 SM-G930F - Android 7.0.0
• LG Nexus 5X - Android 8.1
• Xiaomi Redmi 7 - Android 9.0
• Google Pixel 3a - Android 10.0

Our regular code contributors use these devices (ordered by Android version):

• Xiaomi Redmi Note 4 - Android 7.0
• Samsung Galaxy S4 GT-I9506 - Android 5.0.1
• Samsung Galaxy Tab SM-T285 - Android 5.1.1
• Motorola G 5th Gen XT1671 - Android 7.0

The best way to help us test is to build from source! If you aren't a developer and want to help us test release candidates, join the beta program!

Testing checklists can be found on the Collect testing plan.

If you have finished testing a pull request, please use a template from Testing result templates to report your insights.

Per-commit debug builds can be found on CircleCI. Login with your GitHub account, click the build you'd like, then find the APK in the Artifacts tab.

Current and previous production builds can be found on the ODK website.

Maintainers keep a folder with a clean checkout of the code and use jenv.be in that folder to ensure compilation with Java 1.8.

Maintainers have a local.properties file in the root folder with the following:

sdk.dir=/path/to/android/sdk

Maintainers have a secrets.properties file in the collect_app folder with the following:

// collect_app/secrets.properties
RELEASE_STORE_FILE=/path/to/collect.keystore
RELEASE_STORE_PASSWORD=secure-store-password
RELEASE_KEY_ALIAS=key-alias
RELEASE_KEY_PASSWORD=secure-alias-password

Maintainers also have a google-services.json file in the collect_app/src/odkCollectRelease folder. The contents of the file are similar to the contents of collect_app/src/google-services.json.

When ready to generate a build for the Play Store, maintainers tag the build by adding a release. Tags for full releases must have the format vX.X.X. Tags for beta releases must have the format vX.X.X-beta.X.

To generate official signed releases, you'll need the keystore file, the keystore passwords, a configured collect_app/secrets.properties file, and a configured collect_app/src/odkCollectRelease/google-services.json file. Then run ./gradlew assembleOdkCollectRelease. If successful, a signed release will be at collect_app/build/outputs/apk.

Configure the default JUnit test runner configuration in order to work around a bug where IntelliJ / Android Studio does not set the working directory to the module being tested. This can be accomplished by editing the run configurations, Defaults -> JUnit and changing the working directory value to $MODULE_DIR$.

Source: Robolectric Wiki.

When cloning the project from Android Studio, click "No" when prompted to open the build.gradle file and then open project.

We have seen this problem happen in both IntelliJ IDEA and Android Studio, and believe it to be due to a bug in the IDE, which we can't fix. As a workaround, turning off Instant Run will usually avoid this problem. The problem is fixed in Android Studio 3.5 with the new Apply Changes feature.

If you build the app on your own using Android Studio (Build -> Build APK) and then install it (from an .apk file), you might notice this strange behaviour thoroughly described: #1280 and #1142.

This problem occurs building other apps as well.

If you encounter an error similar to this when running gradlew:

FAILURE: Build failed with an exception

What went wrong:
A problem occurred configuring project ':collect_app'.
> Failed to notify project evaluation listener.
   > Could not initialize class com.android.sdklib.repository.AndroidSdkHandler

You may have a mismatch between the embedded Android SDK Java and the JDK installed on your machine. You may wish to set your JAVA_HOME environment variable to that SDK. For example, on macOS:

export JAVA_HOME="/Applications/Android Studio.app/Contents/jre/jdk/Contents/Home"

Note that this change might cause problems with other Java-based applications (e.g., if you uninstall Android Studio).

If you encounter the java.lang.NullPointerException (no error message). when running gradlew, please make sure your Java version for this project is Java 8.

This can be configured under File > Project Structure in Android Studio, or by editing $USER_HOME/.gradle/gradle.properties to set org.gradle.java.home=(path to JDK home) for command-line use.